Stamping press

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A stamping press ("press") is a manufacturing device that is designed and built to operate progressive stamping dies and other types of dies.

A press has a press frame, a bolster plate and a ram. The bolster plate (or bed) is a large block of metal upon which the bottom portion of a die is clamped; the bolster plate is stationary. Lage presses (like the ones used in the automotive industry) have a die cushion integrated in the bolster plate to apply blank holder forces. This is necessary when a single acting press is used for deep drawing. The ram is also a solid piece of metal that is clamped to the top portion of a (progressive) stamping die and provides the stroke (up and down movement). This action causes the die to produce parts from the metal being fed through it.

Stamping presses can be subdivided into mechanically driven presses and hydraulically driven presses. The most common mechanical presses use an eccentric drive to move the presses ram, whereas hydraulic cylinders are used in hyrauclic presses. The nature of drive system determines the force progression during the rams stroke. The advantage of hydraulic presses is the constant press force during the stroke. Mechanical presses have a press force progression towards the bottom death center depending on the drive- and hinge-system. Mechanical presses therefore can reach higher cycles per time and are usually more common in industrial press shops.

Another classification is single acting presses vs. double (seldom triple) acting presses. Single acting presses have one single ram. Double acting presses have a subdivided ram, to manage for example blank holding (to avoid wrinkles) with one ram segment and the forming operation with the 2nd ram segment.

Typically, presses are electronically linked (with a PLC) to an automatic feeder which feeds metal raw material through the die. The raw material is fed into the automatic feeder after it has been unrolled from a coil and put through a straightener.